Valve announces plans to begin to beta test the Source version of
Counter-Strike. Here's the deal:

COUNTER-STRIKE: SOURCE BETA 1 COMING
SOON

Starting later this summer, Valve will be conducting a limited-time beta of
Counter-Strike: Source via Steam. The beta will first be open to subscribers of
the Valve Cybercafé Program, and then extended to owners of Counter-Strike:
Condition Zero. The next installment of the world’s number 1 online action game,
Counter-Strike: Source blends CS’s intense teamplay with the advanced technology
of Valve’s Source engine. For more information, please visit
www.steampowered.com.